Our neighbors to the north have an unusual problem with their sewage treatment plants. It's not the usual story of aging pipes, insufficient capacity or grease buildup. The big problem in Toronto is dental floss.

Many people flush the floss down the toilet and it can get caught up in the pumps at sanitary pumping stations. Partly to blame are the recent advances in flossing technology with more durable shred-resistant floss now the norm. This is good for your teeth, but the more durable floss doesn't break down as easily and is more likely to gum up the machinery at the local treatment plant.

Floss binds with other waste and creates clumps, which those in the business call the "snowball effect". One clump they found was the size of a softball. So if you use it, throw your floss in the trash when you're done with it.

Now on to the sewage Spills O' the Week:

Malfunction junction: A pump malfunction at the wastewater treatment plant in Salisbury, Maryland caused 3,000 gallons of sewage to spill into the street. City workers quickly cleaned up the spill and contacted the Department of the Environment and local health officials.

-The Daily Times, January 11, 2007

Cover your grass: About 1,000 gallons of raw sewage spilled from a pipe connecting a building to the sewer system and flowed through the streets of Grass Valley, California and into Mattson Creek. Officials blocked off the street for the cleanup and posted warning signs at the creek.

-Theunion.com, January 13, 2007

Trouble in paradise: The Hilo shoreline suffered a 2 million gallon spill of partially treated sewage. The spill occurred when a pump and alarm system failed at the wastewater treatment plant, causing the sewage to be dumped without undergoing chlorination to remove harmful pathogens. Signs were posted around recreational waters warning people to avoid contact.

-The Honolulu Advertiser, January 16, 2007

Root canal: Officials closed a 100 foot stretch of beach along Lower Newport Bay after an overgrown root in a sewer line caused a raw sewage spill of 75 gallons. Tree roots are one of the primary causes of sewage spills in sanitary sewer systems.

-latimes.com, January 17, 2007

Keep pumping: One impact of the recent ice storm across the Midwest that has received little attention is sewage spills resulting from pumping stations losing power. Most larger pumps have backup generators but many smaller pumps do not. Waynesville, Montana experienced at least one sewage spill due to pump failure when raw sewage spilled out of a relief valve and pooled underneath a Route 66 bridge. Officials asked residents to use less water during blackouts to avoid bypasses at pumping stations without electricity.

-Waynesville Daily Guide, January 17, 2007